As part of a continuing investigative effort concerned with the neurobehavioral analysis of the plasticity of the transected human spinal cord, a research program is underway focused upon the habituation of withdrawal reflexes in spinal man. The experimental analysis of factors influencing the retention of habituation is emphasized. Common to each of the studies in this research program is the objective of determining the manner in which afferent stimulation, acting upon the inherent plasticity of the transected spinal cord, can be used as means of controlling the behavior of the divided spinal cord. The research is being conducted at the Texas Institute for Rehabilitation and Research and is supported by the National Institute of Neurological Disease and Stroke.